A mixed gas hollow fiber permeable membrane biofilm system and treatment method for the co-treatment of industrial waste gas, wastewater, and carbon pollution.

Abstract

A hollow fiber permeable membrane biofilm system and treatment method for the co-treatment of industrial waste gas, wastewater, and carbon pollution is disclosed, relating to the resource recovery of industrial waste gas, denitrification of wastewater, and synthesis of polyhydroxyalkanoates. The co-treatment system comprises a reactor, a biofilm system, an influent / effluent circulation system, a multi-source integrated industrial mixed gas supply system, and a control system. This invention achieves efficient treatment of industrial waste gas and wastewater while simultaneously realizing the resource recovery of polyhydroxyalkanoates. Furthermore, by designing a multi-source integrated industrial mixed gas supply system, an intelligent control system, and a large-scale reactor structure, it solves the problems of poor gas source adaptability, low treatment efficiency, and unstable operation in existing technologies.

Description

Technical Field

[0001] This invention relates to a biofilm system and treatment method for industrial waste gas and wastewater treatment. Background Technology

[0002] Current industrial systems generate large amounts of byproduct gases rich in hydrogen (H2) and carbon dioxide (CO2) during production processes, covering core areas such as coking, ammonia synthesis, biomass gasification, and coal chemical industry. Data shows that the global steel and coking industries emit over 200 billion cubic meters of coke oven gas annually, with hydrogen accounting for 55%-60%, and hydrogen content in ammonia synthesis off-gas reaching 50%-70%. These gaseous resources have long been disposed of through combustion or inefficient recovery methods, resulting in the dual pressure of hydrogen energy waste and carbon emissions. Meanwhile, modern wastewater treatment technologies face bottlenecks such as strong carbon source dependence, high operating costs, and low added value of products. For example, while the denitrification coupled polyhydroxyalkanoate (PHA) synthesis technology disclosed in patent CN118270916A can achieve synergistic effects of pollutant removal and biomanufacturing, it still requires the use of NaHCO3 to supplement dissolved inorganic carbon sources and suffers from problems such as pH imbalance and uneven carbon source distribution, hindering its large-scale application.

[0003] Against this backdrop, the innovative gas supply mode of the hydrogen-based mixed gas permeable membrane bioreactor (H2 / CO2-MBfR) offers a breakthrough in solving the aforementioned challenges. The H2 / CO2 mixed gas permeable membrane bioreactor simultaneously delivers a mixture of H2 and CO2 through a hollow fiber membrane, allowing dissolved CO2 to react with water to generate HCO3. - It not only replaces the addition of exogenous NaHCO3, but also releases H2O. + It can also neutralize the OH produced during the denitrification process. - Maintaining pH stability in the reaction system is crucial. However, to achieve large-scale adoption of this technology, the high cost of gas supply is a critical obstacle that urgently needs to be addressed. Using industrial by-product gas as a source for multi-source industrial mixed gas can significantly reduce the overall cost of wastewater treatment and PHA synthesis, while simultaneously creating cross-industry circular economy value.

[0004] Taking the coking industry as an example, approximately 200 m³ of coke oven gas can be recovered per ton after purification via pressure swing adsorption. 3 Hydrogen, when co-introduced into an MBfR system with its 2%-5% CO2 content, can significantly reduce carbon source costs when treating thousands of tons of wastewater with a single unit. In the ammonia synthesis sector, CO2 in purge gas can be directly converted into dissolved inorganic carbon required by microorganisms. Ammonia synthesis companies can reduce reagent costs by millions of yuan annually and lower CO2 emissions through gas source recovery. Even more promising is biomass gasification syngas, whose natural H2 (15%-20%) to CO2 (10%-15%) ratio is highly compatible with MBfR requirements, significantly outperforming single hydrogen source systems.

[0005] The component regulation of industrial syngas further expands the applicability of the technology. By adjusting the proportions of different gas components in coal chemical syngas through water-gas shift reaction, not only can the pH value of the MBfR system be stabilized, but the proportion of different monomers in PHA materials may also be increased, enhancing their mechanical properties. The coupling mode of biogas purification for CO2 and green electricity for hydrogen production can achieve high carbon emission reduction, forming a multi-dimensional synergy of energy, water, and carbon.

[0006] However, the practical application of industrial gas sources still needs to overcome three major technical barriers: First, impurities such as H2S in coke oven gas and CO in syngas may inhibit microbial activity; second, fluctuations in the mixed gas ratio under dynamic operating conditions affect system stability. Summary of the Invention

[0007] This invention proposes a mixed-gas hollow fiber permeable membrane biofilm system and treatment method for the synergistic treatment of carbon pollution in industrial waste gas and wastewater. This system achieves the synergistic treatment of carbon pollution in industrial waste gas and wastewater, while simultaneously enabling the efficient synthesis of polyhydroxyalkanoates (PHA). Furthermore, by designing a multi-source integrated industrial mixed gas supply system, an intelligent control system, and a large-scale reactor structure, it solves the problems of poor gas source adaptability, low treatment efficiency, and unstable operation in existing technologies.

[0008] The mixed gas hollow fiber breathable membrane biofilm system for the synergistic treatment of industrial waste gas, wastewater and carbon pollution of the present invention comprises a reactor (1), a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system;

[0009] The biofilm system includes a membrane module (5) and a gas washing pipeline (20);

[0010] The water circulation system includes an inlet peristaltic pump (6) and a circulating peristaltic pump (7); the outlet of the inlet peristaltic pump (6) is connected to the inlet (4) provided at the lower side of the reactor (1); the inlet of the circulating peristaltic pump (7) is connected to the circulating water outlet (9) provided at the lower side of the reactor (1), and the outlet of the circulating peristaltic pump (7) is connected to the circulating water inlet (11) provided at the upper side of the reactor (1);

[0011] The multi-source industrial mixed gas integrated supply system (21) includes a hydrogen generator (13), a carbon dioxide cylinder (15), a first gas concentration sensor (19), a carbon monoxide cylinder (22), a methane cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixing pressurization cylinder (27), a check valve (28), and a pressurization pump (29); the hydrogen generator (13), the carbon dioxide cylinder (15), the carbon monoxide cylinder (26), the first gas concentration sensor (19), the second gas concentration sensor (27), the second gas concentration sensor (28), and the third gas concentration sensor (29) are all part of the integrated supply system. The outlets of the carbon cylinder (22), methane cylinder (23), and multi-source industrial mixed gas cylinder (24) are connected to the inlet of the check valve (28), respectively. The outlet of the check valve (28) is connected to the inlet of the pressurizing pump (29), and the outlet of the pressurizing pump (29) is connected to the inlet of the secondary mixing pressurizing cylinder (27). The outlet of the secondary mixing pressurizing cylinder (27) is connected to the top inlet (2) and bottom inlet (3) of the membrane module (5), respectively. An electronic device is installed on the secondary mixing pressurizing cylinder (27). A pressure gauge; a mass flow controller (8) is installed on the connecting pipeline between the hydrogen generator (13) and the check valve (28); an electronic pressure reducing valve (14) and a mass flow controller (8) are respectively installed on the connecting pipeline between the carbon dioxide cylinder (15) and the check valve (28), the connecting pipeline between the carbon monoxide cylinder (22) and the check valve (28), and the connecting pipeline between the methane cylinder (23) and the check valve (28). The mass flow controller (8) is installed on the electronic pressure reducing valve (14). On the gas outlet side of the multi-source industrial mixed gas cylinder (24) and the check valve (28), two electronic pressure reducing valves (14), a gas mass flow meter (26) and a second gas concentration sensor (25) are sequentially installed on the connecting pipeline. The second gas concentration sensor (25) is installed on the gas inlet side of the check valve (28), the gas mass flow meter (26) is installed on the gas inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is installed on the gas outlet side of the secondary mixed pressurized gas cylinder (27).

[0012] The control system includes an analog-to-digital converter (12), a PLC controller (17), a heating rod (18), a differential pressure sensor (30), a dissolved oxygen sensor (31), and a pH / temperature sensor (32); the heating rod (18) is located in the middle section inside the reactor (1); the differential pressure sensor (30) is located on the surface of the hollow fiber membrane bundle of the membrane module (5); the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are located at the top overflow weir inside the reactor (1).

[0013] The method for co-treating industrial waste gas, wastewater, and carbon pollution using a mixed gas hollow fiber permeable membrane biofilm system is carried out according to the following steps:

[0014] I. Start-up and operation of the inlet and outlet water circulation system:

[0015] Turn on the inlet peristaltic pump (6) to pump sewage into the reactor (1). The PLC controller (17) controls the inlet peristaltic pump (6) to maintain the hydraulic retention time inside the reactor (1) at 4-24h. Sewage enters the reactor (1) and comes into full contact with the biofilm to achieve denitrification of sewage. The effluent from the reactor (1) is discharged from the overflow weir. At the same time, a part of the sewage inside the reactor is circulated from the circulating water outlet (9) to the circulating water inlet (11) through the circulating peristaltic pump (7) to make the sewage mix evenly and come into full contact with the biofilm. Meanwhile, a part of the biofilm that falls off to the bottom sludge hopper under the action of hydraulic shearing re-attaches to the surface of the membrane module (5) with the circulating sewage to maintain a high content of active organisms.

[0016] II. Start-up and operation of the multi-source industrial mixed gas integrated supply system:

[0017] The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is reduced to 0.2-0.5 MPa through two electronic pressure reducing valves (14) in two stages. Then, it enters the second gas concentration sensor (25) to detect the proportion of each component gas in the multi-source industrial mixed gas cylinder (24). After adjusting the electronic pressure reducing valve (14) at the outlet of the multi-source industrial mixed gas cylinder (24) to make the gas mass flow meter (26) reach the target flow, the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent to the secondary mixing and pressurizing gas cylinder (27). The hydrogen generator (13), carbon dioxide cylinder (15), carbon monoxide cylinder (22), and methane cylinder (23) provide hydrogen, carbon dioxide, carbon monoxide, and methane as raw materials, respectively. The PLC controller (17) adjusts the proportion of the original phase gas entering the secondary mixing pressurized gas cylinder (27) using the raw material gas according to the display result of the second gas concentration sensor (25). The flow rates of hydrogen, carbon dioxide, carbon monoxide and methane are adjusted by the gas mass flow controller (8). At the same time, the PLC controller (17) performs secondary verification of the proportion of the gas output from the secondary mixing pressurized gas cylinder (27) according to the first gas concentration sensor (19). If the partial pressure ratio of hydrogen and carbon monoxide in the gas output from the secondary mixing pressurized gas cylinder (27) deviates from the set value, the PLC controller (17) controls multiple gas mass flow controllers (8) to adjust the raw material gas to ensure that the proportion of each component of the mixed gas entering the membrane module (5) remains stable.

[0018] The pressure of the mixed gas in the secondary mixing pressurized gas cylinder (27) is controlled at 1.5-5 MPa, and the partial pressure ratio of hydrogen to carbon compound in the mixed gas in the secondary mixing pressurized gas cylinder (27) is maintained at (5-9):1. According to the optimal flux requirement of the membrane module (5), the pressure of the mixed gas output from the secondary mixing pressurized gas cylinder (27) is adjusted to 5-20 psig by the electronic pressure reducing valve (14) at the outlet of the secondary mixing pressurized gas cylinder (27) before being sent into the membrane module (5). The optimal flux of the membrane module (5) is 15-30 mL / min.

[0019] III. Reactor Operation:

[0020] (I) Reactor (1) Start-up stage:

[0021] While the mixed gas in the secondary mixing pressurized gas cylinder (27) is introduced into the membrane module (5), hydrogen autotrophic denitrification sludge is inoculated inside the reactor. The sludge inoculation amount is 8-10 g / L. The membrane module (5) is biofilm attached for 10-20 days, during which the influent nitrate load is 2-5 gN / d. After the biofilm is attached, the influent nitrate load is increased to 10-15 gN / d, and the reactor (1) enters the steady-state operation stage. The effluent nitrate concentration of the reactor (1) is less than 5 mgN / L.

[0022] (II) Steady-state operation stage of reactor (1):

[0023] ① pH adjustment: Control the pH of the wastewater inside reactor (1) to 6.0-8.0;

[0024] ② Temperature control: The temperature inside the reactor (1) is controlled at 15~25℃ by controlling the heating rod (18) through the PLC controller (17);

[0025] ③ Inlet and outlet water circulation: The circulating peristaltic pump (7) is controlled by the PLC controller (17) to make the sewage in the reactor (1) circulate once every 1-2 hours;

[0026] ④ Gas supply pressure regulation: When the increase in biofilm thickness causes the membrane flux of membrane module (5) to decrease by more than 15%, the gas supply pressure of the electronic pressure reducing valve (14) at the outlet of the secondary mixing pressurized gas cylinder (27) is increased by the PLC controller (17). The pressure is stabilized when the membrane flux of membrane module (5) recovers to 15-30 mL / min.

[0027] ⑤ Membrane fouling control: When the dissolved oxygen concentration in wastewater exceeds 1.2 mg / L, the membrane flux change rate is calculated using a dissolved oxygen sensor (31). When the membrane flux change rate reaches or is less than -3 mL / min 2At that time, compressed nitrogen is injected into the membrane module (5) through the gas washing pipeline (20) for pulse cleaning, and the surface biofilm of the membrane module (5) is peeled off until the dissolved oxygen concentration in the wastewater does not exceed 1.2 mg / L; if the membrane flux change rate further decreases, 5 g / m³ of nitrogen is added to the wastewater. 3 Denitrifying bacteria enhance biofilm degradation;

[0028] ⑥ Biofilm collection: When the biofilm accumulation on the membrane module (5) exceeds ≥2 mm, biofilm collection is carried out. Compressed nitrogen gas is injected into the membrane module (5) through the gas washing pipeline (20) to form a 0.5-1.5 N / m gas atmosphere on the membrane surface. 2 The hydraulic shear force peels off the surface aged biofilm while retaining the bottom active biofilm. The peeled biofilm is collected in the sludge discharge hopper (10), and the biofilm precipitate in the sludge discharge hopper (10) is rich in PHA.

[0029] ⑦ PHA purification.

[0030] The beneficial effects of this invention are as follows:

[0031] 1. This invention uses a gas concentration sensor to detect multi-source mixed gas components such as H2, CO2, CO, and CH4 in real time, and combines this with supplementary adjustments using raw material gases such as pure H2 and CO2 to ensure that the mixed gas ratio accurately matches the reaction requirements, achieving the optimal H2 / CO2 ratio and realizing dynamic adaptation of each component.

[0032] 2. This invention utilizes a secondary mixing and pressurization technology to homogenize and pressurize the blended gas, solving the problem of uneven composition in industrial waste gas (e.g., coke oven gas contains 55%-60% H2 but low CO2 content), thus controlling the fluctuation range of the partial pressure ratio of the mixed gas within ±3%. Simultaneously, other waste gases in the industrial waste gas, such as H2S and CO, can also be utilized by autotrophic organisms as electron donors.

[0033] 3. This invention is flexible and compatible with various gas sources, and is suitable for industrial gas production such as syngas (H2 / CO), coke oven gas (H2 / CH4), and biomass gas (H2 / CO2 / CH4). The proportion can be dynamically adjusted by a PLC controller to reduce carbon source costs.

[0034] 4. This invention relies on a multi-parameter feedback-dynamic decision-making-execution linkage mechanism built using PLC, enabling millisecond-level precise control of environmental parameters and gas supply. By monitoring changes in pH, temperature, DO, and biofilm thickness in real time, the automatic control module dynamically adjusts the gas flux and pulse cleaning intensity. This reduces fluctuations in operating parameters, decreases the failure rate, extends maintenance cycles, and significantly improves the reliability of continuous industrial operation.

[0035] 5. The device of this invention is equipped with a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system, and an automatic control system in the reactor body, which improves the stability of operation. The control system adjusts the operating conditions such as multi-channel gas flow, mixed gas pressure and flux, pH, temperature, and dissolved oxygen, thereby improving the efficiency of waste gas and wastewater treatment as well as the production efficiency of polyhydroxyalkanoates. It is suitable for large-scale waste gas and sewage treatment and PHA synthesis, and has the advantages of stable operation, strong processing capacity, and simple maintenance.

[0036] 6. This invention uses industrial gas as an inorganic carbon source and achieves synergistic effects on nitrate removal and PHA accumulation by controlling the partial pressure ratio of hydrogen to one-carbon compounds in the feed and utilizing hollow fiber membrane modules as a carrier. During stable operation, almost all nitrates in the wastewater are converted, not only completely removing the nitrogen load from the wastewater but also maintaining the system's high-efficiency denitrification capacity. Simultaneously, the microbial community can complete the synthesis of high levels of PHA within the same cycle, significantly improving the content and purity of the biopolymer products. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the hollow fiber breathable membrane biofilm system for the co-treatment of industrial waste gas, wastewater, and carbon pollution in Example 1.

[0038] Figure 2 This is a schematic diagram of the multi-source industrial mixed gas integrated supply system (21) in Example 1;

[0039] Figure 3 This is a schematic diagram of the structure of the biofilm system in Example 1. Detailed Implementation

[0040] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any reasonable combination of the specific embodiments.

[0041] Specific implementation method one: The mixed gas hollow fiber breathable membrane biofilm system for the synergistic treatment of industrial waste gas, wastewater and carbon pollution in this implementation method consists of a reactor (1), a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system;

[0042] The biofilm system includes a membrane module (5) and a gas washing pipeline (20);

[0043] The water circulation system includes an inlet peristaltic pump (6) and a circulating peristaltic pump (7); the outlet of the inlet peristaltic pump (6) is connected to the inlet (4) provided at the lower side of the reactor (1); the inlet of the circulating peristaltic pump (7) is connected to the circulating water outlet (9) provided at the lower side of the reactor (1), and the outlet of the circulating peristaltic pump (7) is connected to the circulating water inlet (11) provided at the upper side of the reactor (1);

[0044] The multi-source industrial mixed gas integrated supply system (21) includes a hydrogen generator (13), a carbon dioxide cylinder (15), a first gas concentration sensor (19), a carbon monoxide cylinder (22), a methane cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixing pressurization cylinder (27), a check valve (28), and a pressurization pump (29); the hydrogen generator (13), the carbon dioxide cylinder (15), the carbon monoxide cylinder (26), the first gas concentration sensor (19), the second gas concentration sensor (27), the second gas concentration sensor (28), and the third gas concentration sensor (29) are all part of the integrated supply system. The outlets of the carbon cylinder (22), methane cylinder (23), and multi-source industrial mixed gas cylinder (24) are connected to the inlet of the check valve (28), respectively. The outlet of the check valve (28) is connected to the inlet of the pressurizing pump (29), and the outlet of the pressurizing pump (29) is connected to the inlet of the secondary mixing pressurizing cylinder (27). The outlet of the secondary mixing pressurizing cylinder (27) is connected to the top inlet (2) and bottom inlet (3) of the membrane module (5), respectively. An electronic device is installed on the secondary mixing pressurizing cylinder (27). A pressure gauge; a mass flow controller (8) is installed on the connecting pipeline between the hydrogen generator (13) and the check valve (28); an electronic pressure reducing valve (14) and a mass flow controller (8) are respectively installed on the connecting pipeline between the carbon dioxide cylinder (15) and the check valve (28), the connecting pipeline between the carbon monoxide cylinder (22) and the check valve (28), and the connecting pipeline between the methane cylinder (23) and the check valve (28). The mass flow controller (8) is installed on the electronic pressure reducing valve (14). On the gas outlet side of the multi-source industrial mixed gas cylinder (24) and the check valve (28), two electronic pressure reducing valves (14), a gas mass flow meter (26) and a second gas concentration sensor (25) are sequentially installed on the connecting pipeline. The second gas concentration sensor (25) is installed on the gas inlet side of the check valve (28), the gas mass flow meter (26) is installed on the gas inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is installed on the gas outlet side of the secondary mixed pressurized gas cylinder (27).

[0045] The control system includes an analog-to-digital converter (12), a PLC controller (17), a heating rod (18), a differential pressure sensor (30), a dissolved oxygen sensor (31), and a pH / temperature sensor (32); the heating rod (18) is located in the middle section inside the reactor (1); the differential pressure sensor (30) is located on the surface of the hollow fiber membrane bundle of the membrane module (5); the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are located at the top overflow weir inside the reactor (1).

[0046] This embodiment has the following beneficial effects:

[0047] 1. This embodiment uses a gas concentration sensor to detect multi-source mixed gas components such as H2, CO2, CO, CH4, etc. in real time, and combines the raw material gas pure H2, CO2, etc. to supplement and adjust, so as to ensure that the mixed gas ratio is accurately matched to the reaction requirements, and the partial pressure ratio of hydrogen to carbon compounds reaches the optimal ratio, thereby realizing the dynamic adaptation of each component.

[0048] 2. This embodiment utilizes a secondary mixing and pressurization technology to homogenize and pressurize the blended gas, solving the problem of uneven composition in industrial waste gas (e.g., coke oven gas has a H2 content of 55%-60% but a low CO2 content), thus controlling the fluctuation range of the partial pressure ratio of the mixed gas within ±3%. Simultaneously, other waste gases in the industrial waste gas, such as H2S and CO, can also be utilized by autotrophic organisms as electron donors.

[0049] 3. This implementation method is flexible and compatible with various gas sources, and is suitable for industrial gas production such as syngas (H2 / CO), coke oven gas (H2 / CH4), and biomass gas (H2 / CO2 / CH4). The ratio is dynamically adjusted by a PLC controller to reduce carbon source costs.

[0050] 4. This implementation method relies on a multi-parameter feedback-dynamic decision-making-execution linkage mechanism built with PLC, enabling millisecond-level precise control of environmental parameters and gas supply. By monitoring changes in pH, temperature, DO, and biofilm thickness in real time, the automatic control module dynamically adjusts the gas flux and pulse cleaning intensity. This reduces fluctuations in operating parameters, decreases the failure rate, extends maintenance cycles, and significantly improves the reliability of continuous industrial operation.

[0051] 5. The device in this embodiment is equipped with a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system, and an automatic control system in the reactor body, which improves the stability of operation. The control system adjusts the operating conditions such as multi-channel gas flow, mixed gas pressure and flux, pH, temperature, and dissolved oxygen, thereby improving the efficiency of waste gas and wastewater treatment as well as the production efficiency of polyhydroxyalkanoates. It is suitable for large-scale waste gas and sewage treatment and PHA synthesis, and has the advantages of stable operation, strong processing capacity, and simple maintenance.

[0052] 6. This embodiment uses industrial gas as an inorganic carbon source. By controlling the partial pressure ratio of hydrogen to one-carbon compounds in the feed and utilizing a hollow fiber membrane module as a carrier, a synergistic effect is achieved on nitrate removal and PHA accumulation. During stable operation, almost all nitrates in the wastewater are converted, not only completely removing the nitrogen load from the wastewater but also maintaining the system's high-efficiency denitrification capacity. Simultaneously, the microbial community can complete the synthesis of high-content PHA within the same cycle, greatly improving the content and purity of the biopolymer products.

[0053] Specific implementation method two: This implementation method differs from specific implementation method one in that: the top of the reactor (1) is provided with an overflow weir, and the bottom of the reactor (1) is provided with a sludge discharge hopper (10).

[0054] Specific implementation method three: This implementation method differs from specific implementation method one or two in that: the membrane module (5) is set in the middle section of the reactor (1), and a hollow support shaft (33) is set inside the membrane module (5). The support shaft is provided with an air inlet and multiple exhaust holes. The air outlet of the gas washing pipeline (20) is connected to the air inlet of the support shaft, and the air inlet of the gas washing pipeline (20) is connected to an external nitrogen gas source.

[0055] Specific implementation method four: This implementation method differs from one of the specific implementation methods one to three in that the water inlet peristaltic pump (6) and the circulating peristaltic pump (7) are respectively connected to the PLC controller (17) by electrical signals.

[0056] Specific implementation method five: This implementation method differs from one of the specific implementation methods one to four in that: the second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixing pressurized gas cylinder (27), the pressurization pump (29), multiple mass flow controllers (8), multiple electronic pressure reducing valves (14), the first gas concentration sensor (19), and the pressure gauges installed on the secondary mixing pressurized gas cylinder (27) are respectively connected to the PLC controller (17) by electrical signals.

[0057] Specific implementation method six: This implementation method differs from specific implementation methods one to five in that: the differential pressure sensor (30), dissolved oxygen sensor (31) and pH / temperature sensor (32) are respectively connected to the analog-to-digital converter (12) by electrical signals; the analog-to-digital converter (12) is connected to the PLC controller (17) by electrical signals, and the heating rod (18) is connected to the PLC controller (17) by electrical signals.

[0058] Specific Implementation Method Seven: This implementation method for wastewater treatment using a mixed gas hollow fiber breathable membrane biofilm system for the synergistic treatment of industrial waste gas, wastewater, and carbon pollution is carried out according to the following steps:

[0059] I. Start-up and operation of the inlet and outlet water circulation system:

[0060] Turn on the inlet peristaltic pump (6) to pump sewage into the reactor (1). The PLC controller (17) controls the inlet peristaltic pump (6) to maintain the hydraulic retention time inside the reactor (1) at 4-24h. Sewage enters the reactor (1) and comes into full contact with the biofilm to achieve denitrification of sewage. The effluent from the reactor (1) is discharged from the overflow weir. At the same time, a part of the sewage inside the reactor is circulated from the circulating water outlet (9) to the circulating water inlet (11) through the circulating peristaltic pump (7) to make the sewage mix evenly and come into full contact with the biofilm. Meanwhile, a part of the biofilm that falls off to the bottom sludge hopper under the action of hydraulic shearing re-attaches to the surface of the membrane module (5) with the circulating sewage to maintain a high content of active organisms.

[0061] II. Start-up and operation of the multi-source industrial mixed gas integrated supply system:

[0062] The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is reduced to 0.2-0.5 MPa through two electronic pressure reducing valves (14) in two stages. Then, it enters the second gas concentration sensor (25) to detect the proportion of each component gas in the multi-source industrial mixed gas cylinder (24). After adjusting the electronic pressure reducing valve (14) at the outlet of the multi-source industrial mixed gas cylinder (24) to make the gas mass flow meter (26) reach the target flow, the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent to the secondary mixing and pressurizing gas cylinder (27). The hydrogen generator (13), carbon dioxide cylinder (15), carbon monoxide cylinder (22), and methane cylinder (23) provide hydrogen, carbon dioxide, carbon monoxide, and methane as raw materials, respectively. According to the results displayed by the second gas concentration sensor (25), the C controller (17) uses the raw material gas to adjust the proportion of the original phase gas entering the secondary mixing pressurized gas cylinder (27). The flow rates of hydrogen, carbon dioxide, carbon monoxide and methane are adjusted by the gas mass flow controller (8). At the same time, the PLC controller (17) performs secondary verification of the proportion of the gas output from the secondary mixing pressurized gas cylinder (27) according to the first gas concentration sensor (19). If the partial pressure ratio (H / C) of hydrogen and carbon monoxide in the gas output from the secondary mixing pressurized gas cylinder (27) deviates from the set value, the PLC controller (17) controls multiple gas mass flow controllers (8) to adjust the raw material gas to ensure that the proportion of each component of the mixed gas entering the membrane module (5) remains stable.

[0063] The pressure of the mixed gas in the secondary mixing pressurized gas cylinder (27) is controlled at 1.5-2.2 MPa, and the partial pressure ratio (H / C) of hydrogen to carbon compound in the mixed gas in the secondary mixing pressurized gas cylinder (27) is maintained at (5-9):1. According to the optimal flux requirement of the membrane module (5), the pressure of the mixed gas output from the secondary mixing pressurized gas cylinder (27) is adjusted to 5-20 psig by the electronic pressure reducing valve (14) at the outlet of the secondary mixing pressurized gas cylinder (27) before being sent into the membrane module (5). The optimal flux of the membrane module (5) is 15-30 mL / min.

[0064] III. Reactor Operation:

[0065] (I) Reactor (1) Start-up stage:

[0066] While the mixed gas in the secondary mixing pressurized gas cylinder (27) is introduced into the membrane module (5), hydrogen autotrophic denitrification sludge is inoculated inside the reactor. The sludge inoculation amount is 8-10 g / L. The membrane module (5) is biofilm attached for 10-20 days, during which the influent nitrate load is 2-5 gN / d. After the biofilm is attached, the influent nitrate load is increased to 10-15 gN / d, and the reactor (1) enters the steady-state operation stage. The effluent nitrate concentration of the reactor (1) is less than 5 mgN / L.

[0067] (II) Steady-state operation stage of reactor (1):

[0068] ① pH adjustment: Control the pH of the wastewater inside reactor (1) to 6.0-8.0;

[0069] ② Temperature control: The temperature inside the reactor (1) is controlled at 15~25℃ by controlling the heating rod (18) through the PLC controller (17);

[0070] ③ Inlet and outlet water circulation: The circulating peristaltic pump (7) is controlled by the PLC controller (17) to make the sewage in the reactor (1) circulate once every 1-2 hours;

[0071] ④ Gas supply pressure regulation: When the increase in biofilm thickness causes the membrane flux of membrane module (5) to decrease by more than 15%, the gas supply pressure of the electronic pressure reducing valve (14) at the outlet of the secondary mixing pressurized gas cylinder (27) is increased by the PLC controller (17). The pressure is stabilized when the membrane flux of membrane module (5) recovers to 15-30 mL / min.

[0072] ⑤ Membrane fouling control: When the dissolved oxygen concentration in wastewater exceeds 1.2 mg / L, the membrane flux change rate is calculated using a dissolved oxygen sensor (31). When the membrane flux change rate reaches or is less than -3 mL / min 2At that time, compressed nitrogen is injected into the membrane module (5) through the gas washing pipeline (20) for pulse cleaning, and the surface biofilm of the membrane module (5) is peeled off until the dissolved oxygen concentration in the wastewater does not exceed 1.2 mg / L; if the membrane flux change rate further decreases, 5 g / m³ of nitrogen is added to the wastewater. 3 Denitrifying bacteria enhance biofilm degradation;

[0073] ⑥ Biofilm collection: When the biofilm accumulation on the membrane module (5) exceeds ≥2 mm, biofilm collection is carried out. Compressed nitrogen gas is injected into the membrane module (5) through the gas washing pipeline (20) to form a 0.8-1.2 N / m gas atmosphere on the membrane surface. 2 The hydraulic shear force strips 65%-70% of the surface aged biofilm while retaining 0.5-0.8mm of the bottom active biofilm. The stripped biofilm is collected in the sludge hopper (10), and the biofilm precipitate in the sludge hopper (10) is rich in PHA.

[0074] ⑦ PHA purification.

[0075] 1. This embodiment uses a gas concentration sensor to detect multi-source mixed gas components such as H2, CO2, CO and CH4 in real time, and supplements and adjusts them with raw material gas such as pure H2 and CO2 to ensure that the mixed gas ratio is accurately matched to the reaction requirements, and the partial pressure ratio (H / C) of hydrogen to one-carbon compound reaches the optimal ratio, realizing the dynamic adaptation of each component.

[0076] 2. This embodiment utilizes a secondary mixing and pressurization technology to homogenize and pressurize the blended gas, solving the problem of uneven composition in industrial waste gas (e.g., coke oven gas has a H2 content of 55%-60% but a low CO2 content), thus controlling the fluctuation range of the partial pressure ratio of the mixed gas within ±3%. Simultaneously, other waste gases in the industrial waste gas, such as H2S and CO, can also be utilized by autotrophic organisms as electron donors.

[0077] 3. This implementation method is flexible and compatible with various gas sources, and is suitable for industrial gas production such as syngas (H2 / CO), coke oven gas (H2 / CH4), and biomass gas (H2 / CO2 / CH4). The ratio is dynamically adjusted by a PLC controller to reduce carbon source costs.

[0078] 4. This implementation method relies on a multi-parameter feedback-dynamic decision-making-execution linkage mechanism built with PLC, enabling millisecond-level precise control of environmental parameters and gas supply. By monitoring changes in pH, temperature, DO, and biofilm thickness in real time, the automatic control module dynamically adjusts the gas flux and pulse cleaning intensity. This reduces fluctuations in operating parameters, decreases the failure rate, extends maintenance cycles, and significantly improves the reliability of continuous industrial operation.

[0079] 5. The device in this embodiment is equipped with a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system, and an automatic control system in the reactor body, which improves the stability of operation. The control system adjusts the operating conditions such as multi-channel gas flow, mixed gas pressure and flux, pH, temperature, and dissolved oxygen, thereby improving the efficiency of waste gas and wastewater treatment as well as the production efficiency of polyhydroxyalkanoates. It is suitable for large-scale waste gas and sewage treatment and PHA synthesis, and has the advantages of stable operation, strong processing capacity, and simple maintenance.

[0080] 6. This embodiment uses industrial gas as an inorganic carbon source. By controlling the partial pressure ratio of hydrogen to one-carbon compounds in the feed and utilizing a hollow fiber membrane module as a carrier, a synergistic effect is achieved on nitrate removal and PHA accumulation. During stable operation, almost all nitrates in the wastewater are converted, not only completely removing the nitrogen load from the wastewater but also maintaining the system's high-efficiency denitrification capacity. Simultaneously, the microbial community can complete the synthesis of high-content PHA within the same cycle, greatly improving the content and purity of the biopolymer products.

[0081] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the sources of the multi-source industrial mixed gas include fossil fuel gasification, blast furnace gas, converter gas, and coke oven gas, etc., which are mixed gases containing hydrogen and one-carbon compounds such as carbon monoxide, carbon dioxide, and methane produced by industrial production.

[0082] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: in step (II) ①, when pH>8.0, the CO2 content in the mixed gas input to the secondary mixing pressurized gas cylinder (27) is increased to reduce the alkalinity of the solution; when pH<6.0, the CO2 flow rate in the mixed gas is reduced to prevent excessive acidification.

[0083] Specific Implementation Method 10: This implementation method differs from Specific Implementation Methods 1 to 9 in that the PHA purification process is as follows: First, the peeled biofilm is quick-frozen at -80°C, then placed in a freeze dryer and freeze-dried at -60°C for 24 hours to reduce the water content to below 5%; then, it is extracted with a chloroform-ethanol mixed solvent at 50°C for 4 hours, and the extract is obtained by centrifugation to obtain PHA particles with a purity >98%.

[0084] Example 1

[0085] The mixed gas hollow fiber breathable membrane biofilm system for the synergistic treatment of industrial waste gas, wastewater and carbon pollution in this embodiment consists of a reactor (1), a biofilm system, an inlet and outlet water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system.

[0086] The reactor (1) is equipped with an overflow weir at the top and a sludge hopper (10) at the bottom. The overflow weir allows water to be discharged stably to the outside of the reactor (1), preventing microorganisms from flowing directly out of the outlet with the water flow and reducing microbial loss. At the same time, the overflow weir design ensures that the liquid level is constant. In this embodiment, the reactor (1) adopts a cylindrical structure made of acrylic material with a diameter of 320 mm, a height of 1100 mm, and a total volume of 30 L. The membrane module (5) is a non-porous hollow fiber membrane module with a membrane area of ​​15 m². 2 The surface is loaded with a hydrogen autotrophic denitrification biofilm, forming a gas-liquid-film three-phase contact interface.

[0087] The biofilm system includes a membrane module (5) and a gas scrubbing pipeline (20). The membrane module (5) is located in the middle section of the reactor (1). A hollow support shaft (33) is provided inside the membrane module (5). The support shaft is provided with an air inlet and multiple exhaust holes. The exhaust end of the gas scrubbing pipeline (20) is connected to the air inlet of the support shaft. The air inlet end of the gas scrubbing pipeline (20) is connected to an external nitrogen source. The external nitrogen source periodically performs pulse aeration and flushing on the membrane module (5) through the gas scrubbing pipeline (20) to remove the dead biofilm and maintain the proportion of active microorganisms on the membrane surface of the membrane module (5). The biofilm is dominated by hydrogen autotrophic denitrifying bacteria, and simultaneously utilizes H2 as an electron donor and CO2 as an inorganic carbon source to achieve efficient nitrate reduction.

[0088] The inlet and outlet water circulation system includes an inlet peristaltic pump (6) and a circulation peristaltic pump (7). The outlet of the inlet peristaltic pump (6) is connected to the inlet (4) located at the lower side of the reactor (1). The inlet of the circulation peristaltic pump (7) is connected to the circulation water outlet (9) located at the lower side of the reactor (1). The outlet of the circulation peristaltic pump (7) is connected to the circulation water inlet (11) located at the upper side of the reactor (1). The inlet peristaltic pump (6) and the circulation peristaltic pump (7) are respectively connected to the PLC controller (17) by electrical signals. The inlet and outlet water circulation system realizes the transportation of wastewater into the reactor (1) and makes the reactor (1) mixed evenly and fully contact the biofilm on the membrane surface. The wastewater to be treated is injected into the reactor (1) through the inlet peristaltic pump (6). A closed loop of circulating flow is formed through the circulation peristaltic pump (7). The treated water flows upward and exits from the outlet through the overflow weir. By controlling the flow rate of the influent peristaltic pump (7) to adjust the optimal hydraulic residence time, efficient denitrification can be achieved while shortening the treatment time and improving treatment efficiency. At the same time, by controlling the flow rate of the circulating peristaltic pump, while ensuring sufficient contact between the water flow and the biofilm, excessive biofilm shedding is avoided, maintaining high biological activity, and improving mass transfer efficiency and treatment efficiency. Meanwhile, the biofilm that detaches under hydraulic shear will re-attach to the surface of the membrane module through the circulation system to maintain a high content of active organisms.

[0089] The multi-source industrial mixed gas integrated supply system (21) includes a hydrogen generator (13), a carbon dioxide cylinder (15), a first gas concentration sensor (19), a carbon monoxide cylinder (22), a methane cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixing pressurization cylinder (27), a check valve (28), and a pressurization pump (29); the hydrogen generator (13), carbon dioxide cylinder (15), carbon monoxide cylinder (22), methane cylinder (23), and multi-source industrial mixed gas cylinder (24) The outlet ends are connected to the inlet ends of the check valve (28), the outlet ends of the check valve (28) are connected to the inlet ends of the pressurizing pump (29), the outlet ends of the pressurizing pump (29) are connected to the inlet ends of the secondary mixing pressurizing cylinder (27), and the outlet ends of the secondary mixing pressurizing cylinder (27) are connected to the top inlet (2) and bottom inlet (3) of the membrane module (5), respectively; an electronic pressure gauge is installed on the secondary mixing pressurizing cylinder (27); a mass flow controller (8) is installed on the connecting pipeline between the hydrogen generator (13) and the check valve (28); the carbon dioxide cylinder (15) and the check valve (28) are connected to each other. Electronic pressure reducing valves (14) and mass flow controllers (8) are respectively installed on the connecting pipelines between the gas cylinders, the carbon monoxide cylinder (22) and the check valve (28), and the methane cylinder (23) and the check valve (28). The mass flow controller (8) is located on the outlet side of the electronic pressure reducing valve (14). Two electronic pressure reducing valves (14), a gas mass flow meter (26), and a second gas concentration sensor (25) are sequentially installed on the connecting pipeline between the multi-source industrial mixed gas cylinder (24) and the check valve (28). The second gas concentration sensor (25) is set with... On the inlet side of the check valve (28), the gas mass flow meter (26) is set on the inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is set on the outlet side of the secondary mixing pressurized gas cylinder (27); the second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixing pressurized gas cylinder (27), the pressurization pump (29), multiple mass flow controllers (8), multiple electronic pressure reducing valves (14), the first gas concentration sensor (19), and the pressure gauges set on the secondary mixing pressurized gas cylinder (27) are respectively connected to the PLC controller (17) by electrical signals;

[0090] The control system includes an analog-to-digital converter (12), a PLC controller (17), a heating rod (18), a differential pressure sensor (30), a dissolved oxygen sensor (31), and a pH / temperature sensor (32); the heating rod (18) is located in the middle section inside the reactor (1) and is electrically connected to the PLC controller (17); the differential pressure sensor (30) is located on the surface of the hollow fiber membrane bundle of the membrane module (5); the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are located at the top overflow weir inside the reactor (1); the analog-to-digital converter (12) is electrically connected to the PLC controller (17); the differential pressure sensor (30), the dissolved oxygen sensor (31), and the pH / temperature sensor (32) are respectively connected to the analog-to-digital converter (18). 2) Electrical signal connection; The differential pressure sensor (30), dissolved oxygen sensor (31) and pH / temperature sensor (32) in the control system are used to monitor the pH value, dissolved oxygen (DO), temperature and pressure difference inside and outside the biofilm in the reactor (1); The analog-to-digital converter (12) performs analog and digital conversion, and the PLC controller (17) processes the data of pH value, dissolved oxygen, temperature, pressure difference inside and outside the biofilm, pressure of the secondary mixing pressurized gas cylinder (27), gas composition obtained by gas concentration sensor (19) and gas composition obtained by second gas concentration sensor (25), and controls the inlet peristaltic pump (6), circulating peristaltic pump (7), multiple mass flow controllers (8), multiple electronic pressure reducing valves (14), heating rod (18) and pressurization pump (29);

[0091] The method for co-treating industrial waste gas, wastewater, and carbon pollution using a mixed gas hollow fiber permeable membrane biofilm system is carried out according to the following steps:

[0092] I. Start-up and operation of the inlet and outlet water circulation system:

[0093] Turn on the inlet peristaltic pump (6) to pump sewage into the reactor (1). Control the inlet peristaltic pump (6) through the PLC controller (17) to maintain the hydraulic residence time inside the reactor (1) at 6h. Adjust the inlet peristaltic pump (6) in time to obtain the optimal flow rate, meet the treatment effect and improve the treatment efficiency. Sewage enters the reactor (1) and comes into full contact with the biofilm to achieve efficient denitrification of sewage. The effluent from the reactor (1) is discharged from the overflow weir. At the same time, a part of the sewage inside the reactor is circulated from the circulating water outlet (9) to the circulating water inlet (11) through the circulating peristaltic pump (7) to mix the sewage and make full contact with the biofilm. At the same time, a part of the biofilm that falls off to the bottom of the reactor under the action of hydraulic shearing is also re-attached to the surface of the membrane module (5) with the circulating sewage to maintain a high content of active organisms.

[0094] II. Start-up and operation of the multi-source industrial mixed gas integrated supply system:

[0095] The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is reduced to 0.5 MPa through two electronic pressure reducing valves (14) in two stages. Then, it enters the second gas concentration sensor (25) to detect the proportion of each component gas in the multi-source industrial mixed gas cylinder (24). After adjusting the electronic pressure reducing valve (14) at the outlet of the multi-source industrial mixed gas cylinder (24) to make the gas mass flow meter (26) reach the target flow, the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent to the secondary mixing and pressurizing gas cylinder (27). The hydrogen generator (13), carbon dioxide cylinder (15), carbon monoxide cylinder (22), and methane cylinder (23) provide hydrogen, carbon dioxide, carbon monoxide, and methane as raw materials, respectively. The LC controller (17) adjusts the proportion of the original phase gas entering the secondary mixing pressurized gas cylinder (27) using the raw material gas according to the display result of the second gas concentration sensor (25). The flow rates of hydrogen, carbon dioxide, carbon monoxide and methane are adjusted by the gas mass flow controller (8). At the same time, the PLC controller (17) performs secondary verification of the proportion of the gas output from the secondary mixing pressurized gas cylinder (27) according to the first gas concentration sensor (19). If the partial pressure ratio of hydrogen and carbon monoxide in the gas output from the secondary mixing pressurized gas cylinder (27) deviates from the set value, the PLC controller (17) controls multiple gas mass flow controllers (8) to adjust the raw material gas to ensure that the proportion of each component of the mixed gas entering the membrane module (5) remains stable.

[0096] The pressure of the mixed gas in the secondary mixing pressurized gas cylinder (27) is controlled at 1.5 MPa, and the partial pressure ratio (H / C) of hydrogen to carbon compound in the mixed gas in the secondary mixing pressurized gas cylinder (27) is maintained at 7:1. According to the optimal flux requirement of the membrane module (5), the pressure of the mixed gas output from the secondary mixing pressurized gas cylinder (27) is adjusted to 10 psig by the electronic pressure reducing valve (14) at the outlet of the secondary mixing pressurized gas cylinder (27) before being sent into the membrane module (5). The optimal flux of the membrane module (5) is 15-30 mL / min.

[0097] Multi-source industrial mixed gas is a mixture of carbon monoxide and hydrogen, containing other components such as carbon dioxide and methane. Carbon monoxide and hydrogen can serve as electron donors for autotrophic microorganisms and are crucial components of reactor operation. Sources of multi-source industrial mixed gas include fossil fuel gasification, biomass conversion and industrial byproducts such as blast furnace gas, converter gas, and coke oven gas, chemical synthesis, cement manufacturing, oil and gas extraction and processing, power generation, thermal energy industry, and waste incineration. Multi-source industrial mixed gas is often considered one of the main sources of greenhouse gases in industrial production, and controlling and recovering these waste gases is an important direction for carbon emission reduction and resource utilization. In this embodiment, the multi-source industrial mixed gas cylinder (24) uses coke oven gas (55% H2, 25% CH2, and 5% CO2) as the main gas source, supplemented by synthetic ammonia off-gas (65% H2 and 20% CO2) to form the multi-source industrial mixed gas, achieving synergistic carbon and nitrogen treatment through dynamic allocation.

[0098] III. Reactor Operation:

[0099] (I) Reactor (1) Start-up stage:

[0100] While the mixed gas in the secondary mixing pressurized gas cylinder (27) is introduced into the membrane module (5), hydrogen autotrophic denitrification sludge is inoculated inside the reactor at a sludge inoculation rate of 9 g / L. The membrane module (5) undergoes biofilm formation for 15 days, during which the influent nitrate load is 5 gN / d. After the biofilm formation is completed, the influent nitrate load is increased to 15 gN / d, and the reactor (1) enters the steady-state operation stage. The effluent nitrate concentration of the reactor (1) is less than 5 mgN / L.

[0101] (II) Steady-state operation stage of reactor (1):

[0102] ① pH adjustment: The pH of the wastewater inside the reactor (1) is controlled between 6.0 and 8.0. When pH > 8.0, the CO2 content in the mixed gas input from the secondary mixing pressurization gas cylinder (27) is increased to reduce the alkalinity of the solution. When pH < 6.0, the CO2 flow rate in the mixed gas is reduced to prevent excessive acidification.

[0103] ② Temperature control: The temperature inside the reactor (1) is controlled at 15~25℃ by controlling the heating rod (18) through the PLC controller (17);

[0104] ③ Inlet and outlet water circulation: The circulating peristaltic pump (7) is controlled by the PLC controller (17) to make the sewage in the reactor (1) circulate once every 2 hours;

[0105] ④ Gas supply pressure regulation: When the increase in biofilm thickness causes the membrane flux of membrane module (5) to decrease by more than 15%, the gas supply pressure of the electronic pressure reducing valve (14) at the outlet of the secondary mixing pressurized gas cylinder (27) is increased by the PLC controller (17). The pressure is stabilized when the membrane flux of membrane module (5) recovers to 15-30 mL / min.

[0106] ⑤ Membrane fouling control: When the dissolved oxygen concentration in wastewater exceeds 1.2 mg / L, the membrane flux change rate is calculated using a dissolved oxygen sensor (31). When the membrane flux change rate reaches or is less than -3 mL / min 2 At that time, compressed nitrogen is injected into the membrane module (5) through the gas washing pipeline (20) for pulse cleaning, and the surface biofilm of the membrane module (5) is peeled off until the dissolved oxygen concentration in the wastewater does not exceed 1.2 mg / L; if the membrane flux change rate further decreases, 5 g / m³ of nitrogen is added to the wastewater. 3 Denitrifying bacteria enhance biofilm degradation;

[0107] ⑥ Biofilm collection: When the biofilm accumulation on the membrane module (5) exceeds ≥2 mm, biofilm collection is carried out. Compressed nitrogen gas is injected into the membrane module (5) through the gas washing pipeline (20) to form a 0.5-1.5 N / m gas atmosphere on the membrane surface. 2 The hydraulic shear force peels off the surface aged biofilm while retaining the bottom active biofilm. The peeled biofilm is collected in the sludge discharge hopper (10), and the biofilm precipitate in the sludge discharge hopper (10) is rich in PHA.

[0108] ⑦ PHA purification: First, the sloughed biofilm was freeze-dried at -60℃ for 24 hours to reduce the moisture content to below 5%; then, it was extracted with a chloroform-ethanol mixed solvent at 50℃ for 4 hours, and the extract was obtained by centrifugation, yielding PHA particles with a purity >98%; according to the actual conversion rate calculation formula of PHA, the actual conversion rate of PHA reached 57.2%, which is 40%-45% higher than that of the traditional activated sludge process;

[0109] .

Claims

1. A method for sewage treatment by using a mixed gas hollow fiber gas permeable membrane biofilm system with industrial waste gas and wastewater carbon pollution synergistic treatment, characterized in that: The method is carried out according to the following steps: I. Start-up and operation of the water inlet and outlet circulation system: Open the water inlet peristaltic pump (6) to pump sewage into the reactor (1), and control the water inlet peristaltic pump (6) by the PLC controller (17) to maintain the hydraulic retention time in the reactor (1) at 4-24h, so that the sewage enters the reactor (1) and fully contacts with the biofilm to realize the denitrification of the sewage; the reactor (1) outlet water is discharged from the overflow weir; at the same time, part of the sewage in the reactor is circulated by the circulating peristaltic pump (7) from the circulating water outlet (9) to the circulating water inlet (11), so that the sewage is mixed and fully contacts with the biofilm, and at the same time, part of the biofilm falls off under the action of hydraulic shear to the bottom sludge hopper, and then re-attached to the surface of the membrane module (5) to maintain a high active biological content; II. Start-up and operation of the multi-source industrial mixed gas integrated supply system: The multi-source industrial mixed gas in the multi-source industrial mixed gas cylinder (24) is subjected to two-stage stepwise pressure reduction to 0.2-0.5MPa by two electronic pressure reducing valves (14), and then enters the second gas concentration sensor (25) to detect the proportion of each component gas in the multi-source industrial mixed gas cylinder (24), and after the gas mass flow meter (26) reaches the target flow by adjusting the electronic pressure reducing valve (14) at the gas outlet end of the multi-source industrial mixed gas cylinder (24), the original phase gas in the multi-source industrial mixed gas cylinder (24) is sent into the secondary mixed pressurized cylinder (27); the hydrogen generator (13), the carbon dioxide cylinder (15), the carbon monoxide cylinder (22) and the methane cylinder (23) respectively provide hydrogen, carbon dioxide, carbon monoxide and methane as raw material gas; the PLC controller (17) adjusts the proportion of the raw material gas into the secondary mixed pressurized cylinder (27) according to the result displayed by the second gas concentration sensor (25), and adjusts the flow of hydrogen, carbon dioxide, carbon monoxide and methane by the gas mass flow controller (8), and at the same time, the PLC controller (17) verifies the proportion of the gas outlet of the secondary mixed pressurized cylinder (27) by the first gas concentration sensor (19) for the second time, and if the partial pressure ratio of hydrogen to one-carbon compound of the gas outlet of the secondary mixed pressurized cylinder (27) deviates from the set value, the PLC controller (17) adjusts the raw material gas by the plurality of gas mass flow controllers (8) to ensure that the proportion of each component of the mixed gas entering the membrane module (5) remains stable; The pressure of the mixed gas in the secondary mixed pressurized cylinder (27) is controlled at 1.5-2.2MPa, and the partial pressure ratio of hydrogen to one-carbon compound of the mixed gas in the secondary mixed pressurized cylinder (27) is maintained at (5-9):1; the pressure of the mixed gas output from the secondary mixed pressurized cylinder (27) is adjusted by the electronic pressure reducing valve (14) at the gas outlet end of the secondary mixed pressurized cylinder (27) according to the optimal flux requirement of the membrane module (5) to 5-20psig, and then sent into the membrane module (5); the optimal flux of the membrane module (5) is 15-30mL / min; III. Operation of the reactor: (I) Start-up stage of the reactor (1): The mixed gas in the secondary mixed pressurized gas cylinder (27) is introduced into the membrane module (5) while inoculating hydrogen autotrophic denitrification sludge in the reactor, and the sludge inoculation amount is 8-10 g / L. The membrane module (5) is used for biological membrane culturing for 10-20 days, and the nitrate load of the influent water is 2-5 gN / d during the period; after the biological membrane culturing is completed, the nitrate load of the influent water is increased to 10-15 gN / d, and the reactor (1) enters a steady-state operation stage, and the nitrate concentration of the effluent water of the reactor (1) is less than 5 mgN / L; (ii) The reactor (1) in the steady-state operation stage: ① pH adjustment: the pH of the wastewater in the reactor (1) is controlled to be 6.0-8.0; ② Temperature control: the temperature in the reactor (1) is controlled to be 15-25℃ by the heating rod (18) controlled by the PLC controller (17); ③ Influent and effluent water circulation: the influent water in the reactor (1) is circulated for 1-2 h once by the circulating peristaltic pump (7) controlled by the PLC controller (17); ④ Supply gas pressure adjustment: when the biological membrane thickness increases to cause the membrane flux of the membrane module (5) to decrease by more than 15%, the supply gas pressure of the end electronic pressure reducing valve (14) at the gas outlet end of the secondary mixed pressurized gas cylinder (27) is increased by the PLC controller (17), and when the membrane flux of the membrane module (5) is restored to 15-30 mL / min, the pressure is stabilized; ⑤、Membrane fouling control: dissolved oxygen sensor (31) monitors the concentration of dissolved oxygen in sewage more than 1.2mg / L, calculate the membrane flux rate of change, when the membrane flux rate of change reaches or is less than-3mL / min 2 , use gas washing pipeline (20) to inject compressed nitrogen into the membrane module (5) for pulse cleaning, stripping the surface layer of the membrane module (5) biofilm, until the concentration of dissolved oxygen in sewage is not more than 1.2mg / L; if the membrane flux rate of change is further reduced, add 5g / m 3 Denitrifying bacteria agent to strengthen the degradation of biofilm; ⑥, Biofilm collection: when the biofilm on the membrane module (5) accumulates more than 2 mm, the biofilm is collected. Compressed nitrogen is injected into the membrane module (5) through the gas washing pipeline (20) to form a water shear force of 0.5-1.5 N / m 2 on the membrane surface, which peels off the surface aging biofilm while retaining the bottom active biofilm. The peeled-off biofilm is collected in the sludge discharge hopper (10), and the biofilm sediment in the sludge discharge hopper (10) is rich in PHA; ⑦ PHA purification.

2. The method for sewage treatment by using the mixed gas hollow fiber gas permeable membrane biofilm system with industrial waste gas and wastewater carbon pollution synergistically treated according to claim 1, characterized in that: The sources of the multi-source industrial mixed gas include fossil fuel gasification, blast furnace gas, converter gas or coke oven gas.

3. The method for sewage treatment by using the mixed gas hollow fiber gas permeable membrane biofilm system with industrial waste gas and wastewater carbon pollution synergistically treated according to claim 1, characterized in that: In step (ii) ①, when the pH is greater than 8.0, the CO2 content in the mixed gas input by the secondary mixed pressurized gas cylinder (27) is increased to reduce the alkalinity of the solution; when the pH is less than 6.0, the CO2 flow in the mixed gas is reduced to prevent excessive acidification.

4. The method for sewage treatment by using the mixed gas hollow fiber gas permeable membrane biofilm system with industrial waste gas and wastewater carbon pollution synergistically treated according to claim 1, characterized in that: The PHA purification process is as follows: first, the stripped biological membrane is rapidly frozen at-80℃, then placed in a freeze dryer at-60℃ for 24 h to reduce the water content to less than 5%; then extracted with a chloroform-ethanol mixed solvent at 50℃ for 4 h, and the extract is obtained by centrifugal separation, and PHA particles with a purity of >98% are obtained.

5. The method of claim 1 using the mixed gas hollow fiber gas permeable membrane biofilm system for the co-treatment of industrial waste gas and wastewater and carbon pollutants, characterized in that: The multi-source industrial mixed gas hollow fiber gas permeable membrane biological membrane system for the carbon pollution collaborative treatment of industrial waste gas and wastewater comprises a reactor (1), a biological membrane system, an influent and effluent water circulation system, a multi-source industrial mixed gas integrated supply system (21) and a control system; The biological membrane system comprises a membrane module (5) and a gas washing pipeline (20); The influent and effluent water circulation system comprises an influent peristaltic pump (6) and a circulating peristaltic pump (7); the influent peristaltic pump (6) is connected with the influent port (4) arranged on one side of the lower part of the reactor (1); the influent port of the circulating peristaltic pump (7) is connected with the circulating water outlet (9) arranged on one side of the lower part of the reactor (1), and the effluent port of the circulating peristaltic pump (7) is connected with the circulating water inlet (11) arranged on one side of the upper part of the reactor (1); The biological membrane thickness increases to cause the membrane flux of the membrane module (5) to decrease by more than 15%, the supply gas pressure of the end electronic pressure reducing valve (14) at the gas outlet end of the secondary mixed pressurized gas cylinder (27) is increased by the PLC controller (17), and when the membrane flux of the membrane module (5) is restored to 15-30 mL / min, the pressure is stabilized; The multi-source industrial mixed gas integrated supply system (21) comprises a hydrogen generator (13), a carbon dioxide gas cylinder (15), a first gas concentration sensor (19), a carbon monoxide gas cylinder (22), a methane gas cylinder (23), a multi-source industrial mixed gas cylinder (24), a second gas concentration sensor (25), a gas mass flow meter (26), a secondary mixing and pressurizing gas cylinder (27), a check valve (28) and a pressurizing pump (29); the gas outlet ends of the hydrogen generator (13), the carbon dioxide gas cylinder (15), the carbon monoxide gas cylinder (22), the methane gas cylinder (23) and the multi-source industrial mixed gas cylinder (24) are connected with the gas inlet ends of the check valve (28), the gas outlet end of the check valve (28) is connected with the gas inlet end of the pressurizing pump (29), the gas outlet end of the pressurizing pump (29) is connected with the gas inlet end of the secondary mixing and pressurizing gas cylinder (27), and the gas outlet end of the secondary mixing and pressurizing gas cylinder (27) is connected with the top gas inlet port (2) and the bottom gas inlet port (3) of the membrane module (5); an electronic pressure gauge is arranged on the secondary mixing and pressurizing gas cylinder (27); a mass flow controller (8) is arranged on the connecting pipeline between the hydrogen generator (13) and the check valve (28); an electronic pressure reducing valve (14) and a mass flow controller (8) are arranged on the connecting pipeline between the carbon dioxide gas cylinder (15) and the check valve (28), on the connecting pipeline between the carbon monoxide gas cylinder (22) and the check valve (28) and on the connecting pipeline between the methane gas cylinder (23) and the check valve (28), respectively, and the mass flow controller (8) is arranged on the gas outlet side of the electronic pressure reducing valve (14); two electronic pressure reducing valves (14), a gas mass flow meter (26) and a second gas concentration sensor (25) are sequentially arranged on the connecting pipeline between the multi-source industrial mixed gas cylinder (24) and the check valve (28), the second gas concentration sensor (25) is arranged on the gas inlet side of the check valve (28), the gas mass flow meter (26) is arranged on the gas inlet side of the second gas concentration sensor (25), and the first gas concentration sensor (19) is arranged on the gas outlet side of the secondary mixing and pressurizing gas cylinder (27). The control system comprises an analog / digital converter (12), a PLC controller (17), a heating rod (18), a differential pressure sensor (30), a dissolved oxygen sensor (31) and a pH / temperature sensor (32); the heating rod (18) is arranged at the middle section inside the reactor (1); the differential pressure sensor (30) is arranged on the surface of the hollow fiber membrane bundle of the membrane module (5); the dissolved oxygen sensor (31) and the pH / temperature sensor (32) are arranged at the top overflow weir in the reactor (1).

6. The industrial off-gas and wastewater and carbon pollution co-treatment hybrid gas hollow fiber gas permeable membrane biofilm system of claim 5, wherein: An overflow weir is arranged at the top of the reactor (1), and a sludge discharge hopper (10) is arranged at the bottom of the reactor (1).

7. The industrial off-gas and wastewater and carbon pollution co-treatment hybrid gas hollow fiber gas permeable membrane biofilm system of claim 5, wherein: The membrane module (5) is arranged at the middle section of the reactor (1), a hollow support shaft (33) is arranged inside the membrane module (5), air inlet holes and a plurality of air outlet holes are arranged on the support shaft, the gas outlet end of the air washing pipeline (20) is communicated with the air inlet holes of the support shaft, and the gas inlet end of the air washing pipeline (20) is connected with an external nitrogen gas source.

8. The industrial off-gas and wastewater carbon pollution co-treatment hybrid gas hollow fiber gas permeable membrane biofilm system of claim 5, wherein: The water inlet peristaltic pump (6) and the circulating peristaltic pump (7) are respectively connected with the PLC controller (17) through electric signal.

9. The industrial off-gas and wastewater carbon pollution co-treatment hybrid gas hollow fiber gas permeable membrane biofilm system of claim 5, wherein: The second gas concentration sensor (25), the gas mass flow meter (26), the secondary mixed pressurized gas cylinder (27), the pressurized pump (29), the multiple mass flow controllers (8), the multiple electronic pressure reducing valves (14), the first gas concentration sensor (19), and the pressure gauge arranged on the secondary mixed pressurized gas cylinder (27) are respectively connected with the PLC controller (17) through electric signal.

10. The industrial off-gas and wastewater carbon pollution co-treatment hybrid gas hollow fiber gas permeable membrane biofilm system of claim 5, wherein: The differential pressure sensor (30), the dissolved oxygen sensor (31), and the pH / temperature sensor (32) are respectively connected with the analog / digital converter (12) through electric signal; the analog / digital converter (12) is connected with the PLC controller (17) through electric signal; and the heating rod (18) is connected with the PLC controller (17) through electric signal.

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